The 21-Foot Rule Revisited

by
posted on March 16, 2015
** When you buy products through the links on our site, we may earn a commission that supports NRA's mission to protect, preserve and defend the Second Amendment. **
21footrule.jpg

In 1983, Dennis Tueller, a police officer, published an article discussing the need to defend against an attacker armed with a knife or blunt weapon. Through his tests and studies he determined that a person would be in danger if the attacker came at him from 21 feet or less. In short, the attacker could get to his victim before the victim was able to draw and accurately fire his handgun. While this study was done to educate police officers, it obviously is just as important to the armed citizen. However, through the passing years, various interpretations of Tueller's study have led to some confusion. And it is confusion that just might get the armed citizen in trouble.

Suppose that you are forced to shoot an attacker in self-defense. Suppose further that your attacker was armed with a knife and, during your court proceedings you refer to the “21-foot rule” as your justification for using deadly force. And that would be the time that the prosecutor produces an investigating officer who testifies that the actual distance between you and the attacker was 28 feet. Hopefully your attorney would be able to overcome this discrepancy and still convince the court that it was reasonable for you to be in fear for your life. But it has created doubt that just might sway the jury against you.

The simple fact is that 21 feet is an arbitrary distance that may, or may not, relate to your particular situation. To begin with, few people can point to the ground and accurately point out what 21 feet looks like. Secondly, while the Tueller studies are extremely sound, there are a lot of factors that make it an arbitrary distance.

One consideration is the physical condition of your attacker. Obviously, a young man in good condition can cover the ground a whole faster than an old, fat man. How fast the attacker is moving has a great bearing on how quickly he can get within striking distance of his victim.

Another consideration is the condition of the terrain. A person can travel across a smooth floor, or paved parking lot, much faster than he can across rocky ground, or ground that is covered with other obstacles.

The condition of the victim also factors into this question. Are you in good shape, or packing too much weight?  Have the years begun to slow you down?  Are you carrying your defensive handgun openly, or is it concealed in deep cover?  Can your draw and hit in one second, or does it take more like 2½ seconds?  Were you able to step behind cover, or were you caught out in the open?  All of these factors affect how quickly you can respond to this deadly threat. And all of these factors affect how the Tueller studies will relate to you.

If I were going to rely on this premise in the wake of a defensive shooting during police questioning or courtroom testimony, I would never refer to the matter as “The 21-foot Rule.”  I would call it "The Tueller Study." And I would explain that I was concerned with a distance of approximately 21 feet because I never had the opportunity to actually measure the ground between me and my attacker. And I used deadly force because I honestly believed that the bad guy was close enough to place me in fear for my life or serious bodily injury. 

For further information and study on this matter and some training drills, I refer you to the April, 2015 issue of Shooting Illustrated. My friend and co-worker Richard Mann has an excellent article on the matter entitled “Twenty-one Feet.” Just remember that it is “The Tueller Study” and the distance is approximately 21 feet.

 

 

Latest

Gotw Walther Fseries Prox Pmm 1
Gotw Walther Fseries Prox Pmm 1

Gun of the Week: Walther Arms PDP F-Series Pro-X PMM

One of Walther Arms' recent introductions combines the features of several other PDP handguns, meaning the Walther PDP F-Series Pro-X PMM is packed with a number of different design elements.

The Armed Citizen® Oct. 30, 2026

Read today's "The Armed Citizen" entry for real stories of law-abiding citizens, past and present, who used their firearms to save lives.

President's Column | Your Input is Valued

I wish to thank all our members who have sent me e-mails these last 12 months. I’m doing my best to keep up with all your e-mails, but please be aware it seems I’m always 300 to 400 e-mails behind. I want to reiterate that I am reading them all as fast as I have time for.

Building an X-Card Gun for Turkey Shoots

Unofficially known as a “turkey shoot,” X-Card competition challenges shotgunners to place shot pellets as closely as possible to the center of a target. And some makers have perfected a way to fine-tune shotguns for this purpose.

Spanish National Police Adopt Springfield Armory Echelon 4.0FC

The Spanish National Police (Policia Nacional) has officially adopted the Springfield Armory Echelon 4.0FC 9mm pistol as the issue pistol for its uniformed officers.

NRA Launches New NRA.org Platform and Official App to Modernize and Enhance the Member Experience

The National Rifle Association today launched its new NRA.org website and continued enhancements to the official NRA App, marking a major step and significant investment to modernize the organization and better serve members.

Interests



Get the best of American Rifleman delivered to your inbox.